Knot setting device in a feed mechanism for helicoidal wire springs

ABSTRACT

A feeding mechanism in which wire coils are supplied in succession between a pair of belts, clamped by the belts and fed stepwise by the belts until a given plurality of coils are accumulated, whereupon a number of such coils are removed together for assembly as a unit. Each coil has knots at its opposite ends and three mechanisms are arranged in sequence in the path of travel of the coils between the belts for angularly turning those coils located at one end of each of the units in stages in the pauses between stepwise advance of the belts so that such knots in the end coils face the other coils in the opposite direction.

llnited States Patent [191 Spuhl Mar. 27, 1973 KNOT SETTING DEVICE IN AFEED MECHANISM FOR HELICOIDAL WIRE SPRINGS [75] Inventor: Walter Spuhl,Saint Gall, Switzerland [73] Assignee: Spuhl Ag., Saint Gall,Switzerland [22] Filed: Sept. 17, 1971 [2]] Appl. No.: 181,382

[30] Foreign Application Priority Data May 22, 1971 Germany ..P 21 25496.6

[52] US. Cl. ..29/200 A, 29/200 P [51 Int. Cl. ..B23p 19/00 [58] Fieldof Search ..29/200 A, 200 P, 208 R, 200 R [56] References Cited UNITEDSTATES PATENTS 3,503,115 3/ 1970 Kirchner ..29/208 R PrimaryExaminer-Thomas H. Eager Att orneyEric H. Waters et a1.

[ ABSTRACT A feeding mechanism in which wire coils are supplied insuccession between a pair of belts, clamped by the belts and fedstepwise by the belts until a given plurality of coils are accumulated,whereupon a number of such coils are removed together for assembly as aunit. Each coil has knots at its opposite ends and three mechanisms arearranged in sequence in the path of travel of the coils between thebelts for angularly turning those coils located at one end of each ofthe units in stages in the pauses between stepwise advance of the beltsso that such knots in the end coils face the other coils in the oppositedirection.

12 Claims, 8 Drawing Figures KNOT SETTING DEVICE IN A FEED MECHANISM FORHELICOIDAL WIRE SPRINGS BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to a feeding mechanism for helicoidalwire springs adapted to supply the springs for making spring members,said feeding mechanism having two endless belts between which thesprings are clamped and stepwise advanced.

Specifically, the invention is directed to means in said feedingmechanism for positioning the knots formed on the end windings of suchsprings.

2. Prior Art In a known feed mechanism the springs are received by acollector arm from the delivery end of a spring coiling machine andplaced in succession between the belts, the arm being constructed sothat each n" spring is rotated through 180 before insertion between thebelts. When a sufficient number of springs are between the belts, a clawmechanism transfers a group of n springs together to a spring memberfinishing machine. The purpose of turning the n" spring is to bring theknots of the end coils of such spring into reversed position, while theknots of the end coils of all the other springs are in a forward facingposition. In order to 'obtain precise alignment of the knots, it hasfurther been proposed to associate a straightening device with at leastone of the belts, said straightening device including a slide which ismoved after each forward step of the belts, to contact the knot of anend coil adjacent the respective belt and produce a rotation of thespring in question. Displacement of the spring is prevented by acounter-bearing member in the form of a bar. This does not, however,eliminate occasional disturbances which can arise in the collector armespecially at high operational speeds.

SUMMARY OF THE INVENTION An object of the invention is to provide asafer and more quickly acting knot positioning device.

The invention is characterized by the provision of three consecutivemechanisms at least along one of the belts, the first mechanismcomprising a straightening device whose slide can undergo two differentstrokes so that during a pause in the stepwise advance of the belts, theslide acts on a knot in a starting position to displace it either intothe final forward position or into a second position therebeyond; thesecond mechanism including a dolly bar which at a given time passesbehind those end coils whose knots are in the second position, and afurther swivel bar which contacts such knots respectively swinging themtoward said dolly bar to a third position; the third mechanism includinga slide operating in conjunction with a dolly bar to turn each knot inthe third position to a final reversed position.

Viewed in another way wire coils are supplied in succession between apair of belts, clamped by the belts and fed stepwise by the belts untila given plurality of coils are accumulated, whereupon a number of suchcoils are removed together for assembly as a unit. Each coil hasopposite end windings and the knots are formed symmetrically at endwindings, the coils being fed to the belts with their knots oriented inthe same direction. The invention contemplates means arranged in thepath of travel of the coils between the belts for angularly turningselected coils so that their knots face the other coils, said selectedcoils being those coils located at one end of each of said number ofcoils which are removed together to form the unit, said means includingthe aforesaid mechanism for turning said selected coils in stages in thepauses between stepwise advance of the belts.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic top plan viewof two endless belts for the conveyance of wire springs;

FIG. 2 is a diagrammatic elevational view of the ideal position of theknots of the end windings of the springs directly before their take-upinto a machine for assembly of the springs;

FIG. 3 diagrammatically illustrates the operation of the knot settingdevice;

FIG. 4 is a plan view of a swivel mechanism of the knot setting device;

FIG. 5 is a section taken along line VV in FIG. 4;

FIG. 6 is a top view in the direction of arrow VI in FIG. 4 with someparts omitted; and

FIGS. 7 and 8 are respective views corresponding to FIG. 4 of the swivelmechanism in different stages of operation.

DETAILED DESCRIPTION FIG. 1 shows two parallel endless belts l passingaround reversing pulleys 2 with vertical axes. A plurality of helicalwire springs 3 are clamped between oppositely lying runs of the belts.At an inlet end of the endless belts 1 there is a collector arm 5 whichis rotatable about a horizontal axis 4, the arm 5 carrying a gripper 6and operating in known manner to pick up a wire spring 3 from a springmanufacturing unit (not shown) and place the spring into a startingposition designated 3 between belts l. Belts 1 are driven by the pulleys2 stepwise and the operation of arm 5 is coordinated to the drive of thebelts so that a spring 3 is introduced into the position 3 after eachstep of the belts. Finally, for example, ten springs 3 are locatedbetween belts 1. By means of a known gripper mechanism, the first eightsprings 3 for example, are then simultaneously collected and insertedinto a machine for making spring assemblies.

FIG. 2 shows the ideal position of the knots generally indicated at 7 ofthe end coils 8 of the eight front springs adjacent one of the belts 1,said end coils 8 being diagrammatically indicated by circles and theknots 7 by large dots. The knots 7 are symmetrically formed at the endwindings of each spring and the wires are fed to the belts with theknots oriented in the same direction.

It is seen in FIG. 2 that all the knots 7 are in the horizontal medianplane m--m of belts 1. However in the first seven end coils 8 from theleft, the knot is in a front position 7 whereas at the eighth end coil8,, the knot is in a reverse position 7 The reason for this is that, asis well known, that knots 7 should not be placed at the surface of theassembled spring member, in order to avoid damage to coverings and thelike. To obtain the particular position of the end coil 8 the gripper 6was hitherto mounted to swing in the longitudinal direction of arm 5 anda device was provided to ensure that on insertion of the n" spring, e.g.each eighth spring, the gripper was turned through I80". However, theknots 7 were not brought by collector arm 5 into the ideal position asshown in FIG. 2, for which reason a straightening device was employed tocause knots 7, which are slightly below or above the median plane m-m tobe accurately brought into the median plane. Although such straighteningdevice operates excellently, faults can still arise in the knownarrangement. Namely, in the operation of the device which is requiredfrom turning of the gripping device 6 through 180, the risk ofinterruptions increases in proportion to increased speed of operation.

In the present knot setting or positioning device, the swivel feature ofthe gripper 6 is dispensed with. The knot setting device comprises asshown in FIG. 3, three swivel mechanisms 9, and 11, mounted at threelocations along the belts 1, at which the springs 3 stop in the courseof stepwise advance of the belts.

The first swivel mechanism 9 is similar to a conventional straighteningdevice and comprises a slide 12, which is moved after each step of thebelts 1 to cause its working edge 13 to strike the knot 7 of an end coil8 in the position 7 In n l successive operating cycles, the slide 12 isdisplaced in the direction of the arrow to shift the knot 7 to theposition 7,, this being achieved by interposition of a buffer 14 in thepath of travel of working edge 13 in FIG. 3. A counterbearing member inthe form of a stationary horizontal dolly bar engages each end coil toprevent any linear displacement of the end coil of the spring when theknot is moved to position 7 At each n'" working period of slide 12, i.e.when the n'" coil is adjacent slide 12, the buffer 14 is moved out ofthe path of slide 12 so that the stroke of the latter is unimpeded andknot 7 can then reach position 7 namely displaced approximately 90further than the other springs. The buffer 14 can cooperate with theactuator for slide 12, e.g. a piston, rather than with the slide 12itself.

The second swivel mechanism 10 includes a dolly bar 16 and a swing bar17, which can be moved from inactive positions 16 and 17 shown in dottedlines to their active positions shown in solid lines, in order to moveknot 7 to position 7 The third swivel mechanism 11 is again similar to aconventional straightening mechanism and includes slide 12 havingworking edge 13', buffer 14' and dolly bar 15; mechanism 11 differs fromswivel mechanism 9 in that buffer 14' does not have to be removed fromthe path of slide 12, and functions only once during n working periodsof swivel mechanism 9, specifically to bring knot 7 to position 7 i.e.into the median plane m-m in a position 180 rotated relative to 7,. Whenthe respective spring has then reached the front position, knot 7 is inposition 7,, in FIG. 2.

The second swivel mechanism 10 is illustrated in greater detail in FIGS.4-8 and it operates with greater reliability and faster than the swiveldevice formerly used for the gripper 6, so that substantial advantage isobtained in conjunction with the extremely reliable straighteningmechanisms 9 and l 1.

As appears in FIGS. 4-6, the second swivel mechanism 10 comprises acarriage 18 of angle shape with legs 19 and 20. The leg 20 has aslightly bent extension 20' at the top thereof, which is fastened to aframe 23 by screws 21 and spacers 22. Two pillow blocks 25, omitted inFIG. 4, are secured to leg 20 by screws 24 and carry two mutuallyaligned guide bearings 26 for the dolly bar 16. The dolly bar 16 is ofrectangular section and has a vertical surface 28 at an upperwedge-shaped pointed end 27. In the working position of the bar 16 asshown in FIGS. 4 and 5, surface 28 is in contact with the inner surfaceof a respective belt 1 and behind the end coil 8 of spring 3, whose knotis in position 7 in FIG. 3.

In order to displace the dolly bar 16, it is connected to the upperextremity of a rocking lever 31 by means of a pivot 29 which engages ina slot 30 in lever 31. Lever 31 is pivotably mounted on an overhangingportion 19 of the leg 19 by means of a nut 32 and a spacer 33 and thelower extremity 34 of lever 31 lies between two buffers 35 and 36 of acap 38 provided on the free end of a piston rod 37. The cap 38 is guidedbetween two parallel guides 39 fastened to the leg 19 and in theillustrated working position, the cap strikes a rubber buffer 40, whichis fixed to an angle 41 secured to the carriage 18. The piston, notvisible, of the rod 37 is inside a double-acting pneumatic cylinder 42,which is secured to an angle 43 fixedly attached to the carriage 18.When the rod 37 is retracted into the cylinder 42, the dolly bar 16moves to its inactive position 16 shown in broken lines in FIG. 5.

A rectangular baseplate 46 is disposed in a vertical plane parallel tobelt 1 and a projection 46' of the baseplate is attached to the frame 23by screws 44 and spacers 45. The baseplate 46 has two elongated slots 47along its centerline. Two guidepieces 48, fastened by screws 49 to aslide 50, penetrate through the slots 47. A bent extremity 51 of slide50 is connected to a piston rod 52, whose piston is inside adouble-acting pneumatic cylinder 53. The cylinder 53 is attached to anangle 54 secured on the baseplate 46, and two further rubber buffers 55are also mounted on the angle 54 on opposite sides of rod 52. Opposite alikewise bent extremity 56 of slide 50 is a central rubber buffer 57which is attached to an angle 58 secured to the baseplate 46.

An arm .61 is pivoted on slide 50 by a screw 59 with spacer 60, and atension spring 62 has one end attached to the arm 61 and the other endto a bolt 63 fixed to the slide 50. The swing bar 17 is attached to arm61.

A rectangular buffer block 64 is provided with an elongated slot,through which pass two screws 66 by means of which the block 64 can beadjustably attached on baseplate 46. In order to support the block 64when the screws 66 are loosened and the position of the block is beingadjusted, two guide pins are attached to baseplate 46 beneath block 64.

FIG. 7 shows one position of swivel mechanism 10, wherein slide 50 is inits extreme rightward position with its bent extremity 56 adjacentbuffer 57 and the swing bar 17 in its inactive position shown at 17 inFIG. 3, while the dolly bar 16 has already been displaced to itsoperating position by corresponding control of the compressed airsupplied to cylinder 42. -In the inactive position, the swing bar 17 isapproximately aligned with slide 50, while arm 61 adjoins the frontsurface 68 (FIG. 7) of buffer block 64 under the action of spring 62. Ifthe slide 50 is now pulled leftward by cylinder 53, arm 61 will slide onthe edge 69 of block 64, and it will swing together with bar 17 in thedirection of arrow 70. FIGS. 4-6 correspond to the instant when, becauseof this swinging movement the bar 17 meets the knot of end coil 8 lyingin position 7 and thereupon the knot begins to swing backward, while thedolly bar 16 prevents displacement of the end coil 8. As slide 50 movesfurther to the left, the arm 61 comes to rest against the side face 71of block 64 and the task of the swing bar 17 is finished, having carriedthe knot to position 7 It can be seen from FIG. 8 that the hypotheticalcenterline of spring 62 in this extreme working position of the swingbar 17 is also somewhat below the hypothetical axis of rotation of arm61, so that on the next righward movement of slide 50, the spring 62exerts a force on arm 61 to exert a torque thereon in a directionopposite to that of arrow 70 and thus will return bar 17 to its inactiveposition as in FIG. 7.

Before the belts 1 are again moved forward one step, the cylinder 42 isactivated to cause rod 37 to move upward in FIG. 5 and in so doing swingthe lever 31 in the direction of arrow 72 and move the dolly bar to itsinactive position 16,, in which it will not impede the forward motion ofthe next spring 3 on the succeeding forward step. Position 16, isdetermined by contact of lever 31 with a rubber buffer 73 attached tothe lower pillow block 25.

FIG. 5 shows the inside surfaces of both belts l which clamp the spring3. The present knot setting device has only a single swivel mechanism10, since it is sufficient to swing only one knot backward from position7 into position 7 in order for the entire spring to join in thismovement. Thus, the knot at the opposite end of coil 8 willsimultaneously arrive at a position which though not necessarilycorresponding exactly to position 7 is at least approximately thereat.

However, two opposing swivel mechanisms 9 and two facing swivelmechanisms 11 are preferably employed since it is desirable that theknot positions 7 and 7,, be exactly attained at both ends coils 8 of therespective springs 3. Provision of two swivel mechanisms 10 is of coursefeasible, but the expenditure may be unnecessary.

It should further be mentioned that the ideal position of knots 7 shownin FIG. 2 is not absolute, as it is merely required that the knotpositions 7, and 7, be obtained with the first and the last spring. Inthe intervening springs, the knots can lie in position 7, as well as inposition 7 It is simplest ,however for the second and third swivelmechanisms 10 and 11 to operate on only one of n springs instead of withseveral or even n 1 springs. The first swivel mechanism 9 must of courseoperate with each spring namely either until the respective knot fromposition 7 has arrived at position 7,, or until it has reached position7 Depending on the position of the end coil knots at the outlet of thespring coiling machine, it is possible for the mechanism 9 to be mountedbeneath the belts l and the mechanisms 10 and 11 above the belts 1.

What is claimed is:

1. In a feeding mechanism in which wire coils are supplied in successionbetween a pair of belts, clamped by the belts and fed stepwise by thebelts until a given plurality of coils are accumulated, whereupon anumber of such coils are removed together for assembly as a unit, eachcoil having opposite ends windings with knots formed symmetrically atsaid end windings, the coils being fed to the belts with their knotsoriented in the same direction, an improvement comprising means arrangedin the path of travel of the coils between the belts for angularlyturning selected coils so that their knots face in opposite directionsaid selected coils being those coils located at one end of said numberof coils which are removed together to form the unit, said meansincluding mechanisms for turning said selected coils in stages in thepauses between stepwise advance of the belts.

2. An improvement as claimed in claim 1 wherein the coils are fed to thebelts with their'knots facing in the same direction, said means turningsaid selected coils about so that their knots face the knots of theother coils.

3. An improvement as claimed in claim 1 wherein said mechanisms arethree in number and arranged in sequence in the direction of travel ofthe coils adjacent at least one said belt.

4. An improvement as claimed in claim 3 wherein the coils are alignedbetween the belts one after another with their axes in a common plane,the coils being transported by the belts along said-plane, the first ofsaid mechanisms including a transversely movable slide for displacingthe knots of the selected coils to a position offset from said plane,the second of said mechanisms including a swivel bar having a retractedposition out of the path of travel of said coils and an operativeposition in which the bar is pivotably raised to contact the offset knotof a selected coil and angularly displace said knot towards its finalposition, the third of said mechanisms including a transversely movableslide for displacing the knots of the selected coils to their finalangularly displaced positions.

5. An improvement as claimed in claim 4 wherein each said mechanismincludes a counter bearing member acting on the coil in the course ofdisplacement of said knots to prevent linear displacement of said coils.

6. An improvement as claimed in claim 5 wherein said slides of the firstand third mechanisms travel in respective opposite directions.

7. An improvement as claimed in claim 6 wherein said slide of said firstmechanism has two strokes and said first mechanism acts on all coils,said slide undergoing a first longer stroke to displace the knots ofsaid selected coils beyond said plane, and undergoing a shorter secondstroke to bring initially offset knobs of the other coils into saidplane.

8. An improvement as claimed in claim 7 wherein said second mechanismcomprises a pivotal lever connected to said counter bearing member,means slidably supporting said counter bearing member and doubleactingcylinder means coupled to said lever to move the counter bearing memberbetween operative and inoperative positions.

9. An improvement as claimed in claim 8 wherein said counter bearingmember is slidable dolly bar having an extremity adjoining a respectivebelt when said dolly bar is in operative position.

10. An improvement as claimed in claim 7 wherein said second mechanismcomprises a slide member carrying said swivel bar, means for displacingsaid slide member in opposite directions, and an adjustable and fixableblock adjacent said slide member for displacing the swivel bar tooperative position as the slide member v is displaced in one direction.

direction.

12. An improvement as claimed in claim 10 wherein said swivel barincludes a depending arm which is urged by the spring means against afront face of said block in the inoperative position, said arm pivotingabout an edge of said block when raised to operative position andsliding along a side face of said block as the sliding member isdisplaced.

1. In a feeding mechanism in which wire coils are supplied in successionbetween a pair of belts, clamped by the belts and fed stepwise by thebelts until a given plurality of coils are accumulated, whereupon anumber of such coils are removed together for assembly as a unit, eachcoil having opposite ends windings with knots formed symmetrically atsaid end windings, the coils being fed to the belts with their knotsoriented in the same direction, an improvement comprising means arrangedin the path of travel of the coils between the belts for angularlyturning selected coils so that their knots face in opposite directionsaid selected coils being those coils located at one end of said numberof coils which are removed together to form the unit, said meansincluding mechanisms for turning said selected coils in stages in thepauses between stepwise advance of the belts.
 2. An improvement asclaimed in claim 1 wherein the coils are fed to the belts with theirknots facing in the same direction, said means turning said selectedcoils about 180* so that their knots face the knots of the other coils.3. An improvement as claimed in claim 1 wherein said mechanisms arethree in number and arranged in sequence in the direction of travel ofthe coils adjacent at least one said belt.
 4. An improvement as claimedin claim 3 wherein the coils are aligned between the belts one afteranother with their axes in a common plane, the coils being transportedby the belts along said plane, the first of said mechanisms including atransversely movable slide for displacing the knots of the selectedcoils to a position offset from said plane, the second of saidmechanisms including a swivel bar having a retracted position out of thepath of travel of said coils and an operative position in which the baris pivotably raised to contact the offset knot of a selected coil andangularly displace said knot towards its final position, the third ofsaid mechanisms including a transversely movable slide for displacingthe knots of the selected coils to their final angularly displacedpositions.
 5. An improvement as claimed in claim 4 wherein each saidmechanism includes a counter bearIng member acting on the coil in thecourse of displacement of said knots to prevent linear displacement ofsaid coils.
 6. An improvement as claimed in claim 5 wherein said slidesof the first and third mechanisms travel in respective oppositedirections.
 7. An improvement as claimed in claim 6 wherein said slideof said first mechanism has two strokes and said first mechanism acts onall coils, said slide undergoing a first longer stroke to displace theknots of said selected coils beyond said plane, and undergoing a shortersecond stroke to bring initially offset knobs of the other coils intosaid plane.
 8. An improvement as claimed in claim 7 wherein said secondmechanism comprises a pivotal lever connected to said counter bearingmember, means slidably supporting said counter bearing member anddouble-acting cylinder means coupled to said lever to move the counterbearing member between operative and inoperative positions.
 9. Animprovement as claimed in claim 8 wherein said counter bearing member isslidable dolly bar having an extremity adjoining a respective belt whensaid dolly bar is in operative position.
 10. An improvement as claimedin claim 7 wherein said second mechanism comprises a slide membercarrying said swivel bar, means for displacing said slide member inopposite directions, and an adjustable and fixable block adjacent saidslide member for displacing the swivel bar to operative position as theslide member is displaced in one direction.
 11. An improvement asclaimed in claim 10 wherein said second mechanism further comprisesspring means acting on said swivel bar to oppose movement thereof tosaid operative position and to apply force to said swivel bar todisplace the same to inoperative position when the slide member isdisplaced in the opposite direction.
 12. An improvement as claimed inclaim 10 wherein said swivel bar includes a depending arm which is urgedby the spring means against a front face of said block in theinoperative position, said arm pivoting about an edge of said block whenraised to operative position and sliding along a side face of said blockas the sliding member is displaced.